Electrical relay having coaxial terminals



May 9, 1967 J. A. wlTzLER 3,319,200

ELECTRICAL RELAY HAVING coAXIAL TERMINALS Filed June 22, 1965 Y 2 Sheets-Sheet l l 2 WN A N Mm I 1;. C@ O o ,0 .23 24 I 4 JMESA, W/TZLER BY @Wbb May 9, 1967 J. A. wlTzLx-:R

ELECTRICAL RELAY HAVING COAXIAL TERMINALS Filed June 22, 1965 2 Sheets-Sheet 2 Wim m 7 77 r l vl 8 7! n U 5 1 8AM, I e u e 7 l M 7n 66 ./A es A. Mrz/ En INVENTOR 22 B /Z//Mw'uf r'roR/vEr United States Patent O 3,319,200 ELECTRICAL RELAY HAVING COAXIAL TERMINALS James A. Witzler, Boonton, NJ., assignor to Branson Corporation, Denville, N J., a corporation of Delaware Filed June 22, 1965, Ser. No. 465,843 9 Claims. (Cl. 335-196) This invention relates to electrical relays and more particularly to a novel construction and arrangement of the relay contacts and connection terminals.

Sealed miniature electrical components are of increasing interest to industry. In the miniaturization of sealed relays, the size to which the device can be reduced and the number of contacts incorporated therein, is limited by the number of terminals which can be carried by the base, or header, of the relay. Appropriate spacing of the terminals is required to provi-de necessary dielectric strength and contact isolation. This invention is directed to a relay construction incorporating coaxial terminals and a double-deck internal contact switching arr-angement. In such construction, approximately twice the number of isolated electrical terminals can be carried by the header, as compared to conventional arrangements utilizing single wire terminals. In addition, the movable and stationary contacts of the relay are arranged in two planes, which provides for a doubling of the relay switching capacity with only a very small increase in relay height.

An object of this invention is the provision of an electrical relay which can be made in a given small size while providing an increased number of electrically isolated contacts.

An object of this invention is the provision of an electrical relay wherein the movable and dixed contacts are carried by coaxial terminals extending through a header.

An object of this invention is the provision of an electrical relay having a plurality of coaxial terminals carried by a base, axially-spaced stationary contacts carried by certain -of the terminals, movable contacts carried by other of the terminals, an operating coil supported from the base, and armature means effective upon energization of the operating coil to swit-ch the movable contacts from `one to another set of cooperating stationary contacts.

An object of this invention is the provision of an electrical relay having a plurality of coaxial terminals carried by a header, flexible leaf springs secu-red to certain of the terminals and having ends arranged for engagement with other of the terminals, an operating coil supported from the header and means actuated by the operating coil to liex the leaf springs into engagement with the said other terminals.

These and other objects and advantages of the invention will become apparent from the following description when taken with the accompanying drawings. It will be understood, however, that the drawings are for purposes of illustration and are not to be construed as dening the scope or limits of the invention, reference being had for the latter purpose to the claims appended hereto.

In the drawings wherein like reference characters denote like parts in the several views:

FIGURE 1 is a side elevational view of a relay made in accordance with one embodiment of this invention; -FIGURE 2 is a front elevational view as viewed from the left side of FIGURE l;

FIGURE 3 is a top plan view thereof;

FIGURE 4 is a similar top plan View but with the operating coil and armature omitted;

FIGURE 5 is an enlarged, central cross-sectional view showing the construction of the coaxial terminal;

` 3,319,200l Patented May 9, 1967 FIGURE 6 is a similar View showing the axially-spaced contacts secured to such terminal;

FIGURE 7 is an exploded isometric view showing a relay made in accordance with another embodiment of this invention with portions of certain members broken away;

FIGURE 8 is an enlarged isometric view showing one of -the upper stationary contacts of the relay shown in FIGURE 7;

FIGURE 9 is a similar view of the lower stationary contact; `and FIGURE 10 is an end elevational view of the base and contact assembly shown in FIGURE 7, drawn to an enlarged scale and with one contact terminal set shown in cross-section.

Reference now is made to FIGURES 1-4. The header, or base 10, made of non-magnetic material, is provided with a peripheral flange for supporting the open end of a metal cover, not shown, which cover is soldered or welded to the base to form a hermetically-sealed device. A pair of pin terminals 12 extend through the base, such terminals being electrically insulated from the base by glass-to-metal, or ceramic-to-metal seals, as is conventional in the header art. The ends of the relay operating coil 13 are connected to these pin terminals, said coil being supported in operative position by means of a pair of softiron brackets 14 and 15 as by means of screws threaded into holes formed in the ends of the soft-iron core. The lower ends of these brackets rest upon the surface 'of the base and have extended lower end portions of reduced width received in the transverse recesses 16 formed in the base. These brackets are secured to the base by soldering or welding.

In accordance with this invention, a plurality of similar coaxial terminals also extend through the base 10. The construction of such terminals is shown in FIGURE 5, which is a vertical, cross-sectional view thereof. An inner wire 18 is coaxially positioned with respect to an outer metal tube 19 and electrically insulated therefrom by a suitable dielectric material 20, such as glass, or ceramic. The outer tube is electrically insulated from the base by a glass, or ceramic bead 21. Thus, the two terminal members 18 and 19 are electrically insulated from each other and the base 10 while providing hermetically sealed joints therebetween. The lower, exposed end of the tube 19 may be ared outwardly and the center wire 18 may be provided with a circumferentiallygrooved head 22, for the purpose of facilitating the attachment and soldering of lead wires thereto. Generally, the wire 18 and the tube 19 are made of a metal alloy having a temperature coefficient of expansion matched to that of the insulating members and the header, or base 10.

The described coaxial terminal serves to support spaced, stationary contacts of the relay, as shown in the corresponding view of FIGURE 6. The contact assembly comprises an insulating member 23 encircling the outer tube 19 and resting on the base 10. A lower Contact 24 is inserted over the tube 19 and soldered thereto. A second insulating washer 25 is inserted over the central wire 18, after which an upper contact 26 is positioned over the exposed portion of the wire and soldered or brazed thereto. Each of the contacts 24 and 26 are in the form of circular bushings and are made of a material having good electrical contact characteristics such as, for example, silver, gold, platinum alloy, etc. Alternatively, the contacts can be made of a base metal and overlaid with a material having a desired contact characteristic. Also, it will be apparent that the lower insulating washer 23 can be omitted when insulating bead 21 has an 'outside diameter exceeding that of the lower contact 24.

Referring again to FIGURES 1 4, the lower contact 24 and the upper Contact 26 constitute a iirst set of axially- V u spaced, stationary contacts. Spaced from such assembly is a similar terminal-contact assembly having corresponding lower and upper contacts, the upper such contact 26 being visible in FIGURES 3 and 4. An upper, thin, leaf spring 28 has an arcuate end partially encircling the upper contact 26 and soldered thereto. A similar leaf spring 29 has its arcuate end soldered to the lower contact positioned under the upper contact 26. These springs, made of a suitable material, such as beryllium copper, nickelsilver, or other high conductivity spring alloys, have their free ends extending beyond and normally in engagement with the cooperating stationary contacts 26 and 24. Preferably, the leaf springs may be plated with silver, thereby to facilitate the soldering of the arcuate ends to their associated contacts and to provide a'good electrical contact with the associated stationary contacts 26 and 24.

A similar set of leaf springs 28a and 29a have arcuate ends secured to a similar terminal-contact assembly (identified by the numeral 30 in FIGURES 3 and 4) and their free ends normally engaging the associated upper and lower stationary contacts of the terminal-contact assembly identified by the numeral 30.

Spanning the coil-supporting brackets 14 and 15 is a fiat bar 31, made of a non-magnetic material, said bar being disposed in slots formed in the brackets and welded thereto. An armature 32, made of soft-iron, is pivotally secured to the bar 31 by a rivet passing through centralaligned holes formed in the armature and the bar. As seen in FIGURE 2, the bracket 14 includes an integral projection 34 lying to one side of a vertical plane containing the axis of the operating coil 13. A similar projection is formed on the bracket 15. These projections lie on opposite sides of the armature 32. Thus, when the operating coil is energized, the armature is caused to rotate from the normal position, shown in FIGURE 3, in a clockwise direction into engagement with the two projections of the brackets.

nWelded to the left end of the armature 32 is an L- shaped wire 35 carrying a bushing 36 made of glass, or ceramic. A similar wire 35' and bushing 36' are carried by the other end of the armature. When the operating coil is deenergized, the free ends of the leaf springs 28 and 29 are in engagement with the associated stationary contacts 26 and 24. In relay terminology, the leaf springs constitute movable contacts and the lstationary contacts 26 and 24 constitute back contacts. The associated front contacts comprise a similar coaxial terminal-contact assembly, the upper and lower contacts of such assembly being visible in FIGURE 2 and identified by the numerals 26a and 24a, respectively. When the operating coil is energized, the bushing 36 exes the leaf springs 28 and 29 out of engagement with their associated back contacts 26 and 24 and into engagement with the associated front contacts 26a and 24a. It will be clear, now, that the upper leaf spring 28 and its associated stationary contacts 26 and 26a constitutes a single-pole, d-ouble-throw switch and that the lower leaf spring 29 and its associated -stationary contacts constitute a second single-pole, doublethrow switch.

The other two leaf springs 28a and 29a normally are in engagement with their associated upper and lower back contacts forming part of a coaxial terminal-contact assembly identified by the numeral 30 in FIGURE 4. The associated front contacts are visible in FIGURE l and are identified by the numerals 30a and 30b, respectively. Thus, the relay is provided with four (4) electrically-independent singleapole, double-throw contact arrangements.

From the above description it will be apparent that with the coaxial terminal-contact construction, the internal switching structure of the relay is arranged in two planes. Further, the coaxial terminal arrangement permits the incorporation of twice the number of electrically-insulated terminals, in a given header, while maintaining an appropriate spacing to provide good electrical isolation between all of the terminals and the relay base. Thus, the

described relay construction permits manufacture of miniature relays having an increased switching capacity with only a very small increase in the height of the relay.

A modification of the relay construction is shown in FIGURES 7-10. As shown in FIGURE 7, the relay operating coil 13' is carried by the base portion of an inverted, generallyVU-shaped bracket 55, the side arms of which terminate in leg portions 56. A soft-iron strap 57 partially surrounds the coil and is provided with spaced ends, or pole pieces, 58 and 59. The strap 57, bracket 55 and the coil 13 are secured together by means of screws threaded into holes provided in the ends of a soft-iron core passing through the coil, the upper screw 60 being visible in this particular view. The armature 62 has welded thereto a shaft 63 having ends extending through aligned holes formed in the side arm portions of the bracket 55. A suitable spring, not shown, biases the armature to the normal position, as shown. When the coil is energized, the magnetic attraction causes the armature to rotate so that its opposite ends engage the pole pieces 58 and 59.

The relay base, or header 10', carries the pins 12, for connection to the ends of the operating coil, and a plurality of coaxial terminals, identified by the numerals 65-70, each such terminal being made as shown in FIG- URE 5. With specific reference to the coaxial terminal 65, this terminal carries a lower stationary contact 71, an upper stationary contact 72, and the insulator spacing washers 73 and 74. The lower stationary contact 71, also shown in the enlarged isometric view of FIGURE 9, cornprises a rigid arm 75 soldered to a bushing 76. The hole 77, extending through the arm and the bushing, has a diameter such that the contact 71 is slidably insertable over the outer tube 19 (see FIGURE 6) of the coaxial terminal. The upper stationary contact 72, shown in the enlarged isometric view of FIGURE 8, comprises a rigid arm 78 soldered to the bushing 79. .In this case, the hole 80, extending through the arm and the bushing, has a diameter such that the contact is. slidably insertable over the center wire 18 (see FIGURE 5) of the coaxial terminal. Similar lower and upper stationary contacts 71 and 72 are carried by the coaxial terminal-contact as- I sembly identified by the numeral 66. These contacts, however, are reversely-disposed with respect to the contacts 71 and 72 carried by the terminal assembly 65.

The described arrangement of the two sets of spaced stationary contacts will best be understood by reference to FIGURE l0, which shows theV coaxial terminal assembly 65 in end elevation and the coaxial terminal assembly 66 in central, cross-section. It will be noted that the lower Contact 71 and the upper contact 72 are assembled to the terminal 65 with their respective rigid arms 78 and 75 lowermost. On the other hand, the similar lower co-ntact 71 and the upper Contact 72 are assembled on the terminal 66 with their respective rigid arms 75 and 78' uppermost. This results in a vertical spacing between the rigid arms while affording economy of manufacture in that the lower contacts are of identical construction, as are the upper contacts.

Referring back to FIGURE 7, the coaxial terminal assembly 67 carries an insulator washer 82 and a lower bushing 83 having the lower leaf spring 84 soldered thereto. This leaf spring has a hole formed therein, corresponding to the hole 77 of the contact 71 shown in FIG- URE 9, whereby the contact 83 and the leaf spring are slidably insertable over the outer tube of the coaxial terminal. An upper leaf spring 85 is soldered to the upper bushing 86, said spring and bushing having a through hole similar to the hole of the upper contact 72 shown in FIGURE 8, whereby the spring and bushing are slidably insertable over the center wire of the coaxial terminal. In the assembly, the lower and upper bushings are soldered, respectively, to the outer tube and the center wire of the terminal and are electrically insulated from each other by the washer 87. The leaf springs have se- Cured thereto insulator buttons v88 and 89 andthe free ends of both springs extend between the rigid arms of the stationary contacts carried by the terminals 65 and .66. As shown in FIGURE l0, these springs are flexed upwardly so that the end of the lower spring 84 normally engages the4 arm 75 of the lower contact 71, whereas the end of the upper spring 85 normally engages the arm 78 of the upper contact 72'.

Again referring to FIGURE 7, vthe coaxial terminal assembly 68 carries a pair of similar leaf springs 91 and 92, having lfree ends 'extending between the rigid arms of similar stationarycontacts carried by the coaxial terminal assemblies 69 and 70. The relay armature 62 carries two, downwardlyextending pins, which are not visible in this particular view. When the relay operating coil is assembled to the base, the supporting legs 56 are disposed within `the transverse notches 95 formed in the base and soldered in place. When the armature is in the illustrated, relay-deener'gized position, the pin carried by the left end of the armature engages the insulator button 96 and flexes the upper leaf spring 91 downwardly, and, by reason of the insulator button 97, the lower leaf spring 92 also is flexed downwardly. This causes the ends of these leaf springs normally to engage the lower rigid arms of the stationary contacts carried by the coaxial terminal assemblies 69 and 70. In such normal, armature position, the other pin, carried at the right hand end of the armature, is spaced from the insulator button 89 whereby the ends of the leaf springs 84 and 85 are in engagement with the upper rigid arms of the stationary contacts carried by the coaxial terminal assemblies 65 and 66. When the operating coil is energized, the armature rotates, thereby providing a switching action so that the ends of the leaf springs 91 and 92 are permitted to ex upwardly and into engagement with the upper arms of the associated stationary contacts and the leaf springs 84 and 85 are flexed downwardly so that their ends engage the lower arms of the associated stationary contacts. This transfer, or switching action, is shown in FIGURE 10, wherein the leaf springs 84 and 85 are shown in engagement with the upper stationary contact arms 75 and 78 when the relay is in the deenergized condition. In the relay-energized condition the springs 84 and 85 are flexed downwardly out of engagement with the upper arms 75' and 78 and into engagement with the lower arms 75 and 78, as shown by the dotted lines. v

It will be apparent that the relay shown in FIGURE 7 is also provided with four (4) sets of single-pole, double-throw contacts. In this case, the movable contacts operate in planes normal to that of the base, whereas in the relay shown in` FIGURES 1-4 the movable contacts operate in planes parallel tothat of the base.

While the relays described herein include a metal, nonmagnetic base to which the coaxial terminals are secured by means well known in the header art, the base can be made of an insulating material such as plastic, or ceramic. Also, the pin terminals to which the ends of the operating coil are connected can also be of the described coaxial terminal arrangement, thereby permitting the use of two, electrically-independent operating coils. Further, the combination and arrangement of the operating coil and armature may be varied to meet specific design and operating requirements. These and other variations and modications may -be made without thereby departing from the spirit and scope of the invention as recited in the following claims.

I claim:

1. A relay comprising,

(a) first and second coaxial terminals extending through a base,

(b) a pair of stationary contacts carried by the rst coaxial terminals and electrically isolated from each other, said contacts being spaced axially of the terminals,

(c) a pair of movable contact members carried by the second coaxial terminals and electrically isolated from each other,

(d) an operating coil carried by the base, and

(e) switching means for effecting engagement of the movable Contact members with the stationary contacts when the operating coil is energized.

2. The invention as recited in claim 1, wherein the stationary contacts are bushings having substantially the same diameter and wherein said movable contact members are flexible leaf springs having ends lying in a plane substantially parallel to the axis of the said bushings.

3. The invention as recited in claim 1, wherein the stationary contacts are spaced arms lying in a plane substantially parallel to that of said base, and wherein said movable contact members are flexible leaf springs vhaving ends co-planar with the said spaced arms.

4. Arelay comprising,

(a) abase,

(b) an operating coil carried by the base,

(c) an .armature magnetically-coupled to the operating coil,

(d) a first coaxial terminal extending through the base, said terminal comprising an outer tubular conductor electrically insulated from the base and a central conductor electrically insulated from the tubular conductor,

(e) a pair of stationary contacts carried by said first coaxial terminal, one contact being connected to the tubular conductor and the other contact being connected to the central conductor,

(f) a second similar coaxial terminal extending through the base,

(g) a pair of flexible leaf springs carried by the second coaxial terminal, one spring having an end connected to the tubular conductor and the other spring having an end connected to the central conductor, and

(h) actuating means carried by the armature and exing each leaf spring into engagement with an associated stationary contact when the operating coil is energized.

5. The invention as recited in claim 4, wherein the stationary contacts and leaf springs lie in planes normal to that of thesaid base.

6. The invention as recited in claim 4, wherein the stationary contacts and leaf springs lie in planes parallel to that of the said base.

7. Arelay comprising,

(a) abase,

(b) first coaxial terminals extending through the base and carrying a first pair of stationary c-ontacts which are electrically isolated from each other,

(c) second coaxial terminals extending through the base and carrying a second pair of stationary contacts which are electrically isolated from each other,

(d) third coaxial terminals extending through the base and carrying a pair of exible leaf springs, which springs are electrically isolated from each other and have ends extending beyond and normally engaging the said first pair of stationary contacts,

(e) an operating coil carried by the base,

(f) an armature magnetically-coupled to the operating coil, and

(g) means carried by the armature for flexing the said leaf springs out of engagement with the first pair of stationary contacts and into engagement with the second pair of stationary contacts when the operating coil is energized.

8. The invention as recited in claim 7, wherein the first and second pairs of stationary contacts are 'bushings having substantially the same outside diameters, and wherein the rst and second pairs of leaf springs lie in planes normal to the planes of the said base 9. Arelay comprising,

(a) abase,

(-b) a rst pair of coaxial terminals extending through the base and carrying a rst pair of lower and upper stationary contacts, said contacts having spaced arms lying in planes parallel to that of the base,

(c) a second pair of coaxial terminals extending through the base and carrying a second pair of lower end upper stationary contacts having spaced arms lying in planes parallel to that of the base,

(d) a third pair of coaxial terminals carrying a pair of llexible leaf springs, one `leaf spring having an end extending between the arms of the lower stationary contacts and the other leaf spring having an end extending between the arms of the upper stationary contacts,

(e) an operating coil carried by the base,

(f) an armature magnetically-coupled to the operating coil, and

(g) means carried by the armature for flexing the ends of the leaf springs for transfer engagement with the arms of the associated. upper and lower stationary contacts in correspondence with energization and deenergization of the operating coil.

References Cited by the Examiner UNITED STATES PATENTS FOREIGN PATENTS 6/ 1963 Germany.

BERNARD A. GILHEANY, Primary Examiner.

B. DOBECK, Assistant Examiner. 

1. A RELAY COMPRISING, (A) FIRST AND SECOND COAXIAL TERMINALS EXTENDING THROUGH A BASE, (B) A PAIR OF STATIONARY CONTACTS CARRIED BY THE FIRST COAXIAL TERMINALS AND ELECTRICALLY ISOLATED FROM EACH OTHER, SAID CONTACTS BEING SPACED AXIALLY OF THE TERMINALS, (C) A PAIR OF MOVABLE CONTACT MEMBERS CARRIED BY THE SECOND COAXIAL TERMINALS AND ELECTRICALLY ISOLATED FROM EACH OTHER, (D) AN OPERATING COIL CARRIED BY THE BASE, AND (E) SWITCHING MEANS FOR EFFECTING ENGAGEMENT OF THE MOVABLE CONTACT MEMBERS WITH THE STATIONARY CONTACTS WHEN THE OPERATING COIL IS ENERGIZED. 